According to AMD only 3 cores can be in turbo mode at a time, and since turbo is controlled by the CPU itself I doubt 4 cores are getting boosted, I'd say CPU-Z is a bad tool to use since it doesn't update often enough to see whats actually going on.
For example on a dual core Phenom II @ 3.4GHz (CnQ enabled) I ran 2 instances of CPU-Z (one for each core) and at the same time ran a program set to take 10 samples per second, the yellow line is P-state (in percentage) and the blue line is the MHz usage, watching core 0 CPU-Z only detected the CPU speed changing two times when it changed at least 10 times.
http://img263.imageshack.us/img263/9981/cpumhz.png
Thanks for sharing your X6 results! :up:
.